|Creep of a Silicon Nitride Under Various Specimen/Loading Configurations - Choi, Sung R.|
Extensive creep testing of a hot-pressed silicon nitride (NC132) was performed at 1300 C in air using five different specimen/loading configurations, including pure tension, pure compression, four-point uniaxial flexure, ball-on-ring biaxial flexure, and ring-on-ring biaxial flexure. Nominal creep strain and its rate for a given nominal applied stress were greatest in tension, least in compression, and intermediate in uniaxial and biaxial flexure...
Keywords: AEROSPACE SAFETY; MANAGEMENT PLANNING; RISK; SPACE SHUTTLES; MISSION PLANNING; X-33 REUSABLE LAUNCH VEHICLE; X-34 REUSABLE LAUNCH VEHICLE; X-38 CREW RETURN VEHICLE
|Quantitative Infrared Spectroscopy of Minor Constituents of Earth's Atmosphere - Chackerian, Charles, Jr.|
Infrared spectroscopic techniques have become extremely powerful tools for use in achieving a number of observational objectives in understanding and monitoring the health of Earth s atmosphere. Prerequisite to designing appropriate instruments well as to interpreting the observations that monitor the important molecular species, quantitative laboratory spectroscopic measurements must be done. measurements provide (1) line and band intensity values that are needed to establish limits of detectab...
Keywords: X-34 REUSABLE LAUNCH VEHICLE; THERMAL PROTECTION; AEROTHERMODYNAMICS; ABLATIVE MATERIALS; RUDDERS; THERMAL ANALYSIS; NAVIER-STOKES EQUATION
|NASA Destination Tomorrow - DT11 - RLVs - NASA LaRC Office of Education|
NASA Destination Tomorrow Segment describing the next generation of reusable launch vehicles (RLVs).
Keywords: On The Runway; Reusable Launch Vehicle; RLV; Space Shuttle; Stephanie Sy; Charlie Cockrell
|An Approach to Simulation of Extreme Conditions for a Planetary Lander - Queen, Eric M.|
A ''Monte Carlo-like'' design analysis tool is developed and applied to an aeromaneuvering Mars entry vehicle. This tool provides realistic but challenging design cases using many fewer cases than a full Monte Carlo analysis. The problem of random input variables that are provided a priori (as opposed to being drawn from a given distribution) is addressed and a solution is found that shows prospects for future improvement.
Keywords: AEROSPIKE ENGINES; PLUMES; X-33 REUSABLE LAUNCH VEHICLE; HEAT FLUX; SEA LEVEL; THRUST
|Pathway Concepts Experiment for Head-Down Synthetic Vision Displays - Prinzel, Lawrence J., III|
Eight 757 commercial airline captains flew 22 approaches using the Reno Sparks 16R Visual Arrival under simulated Category I conditions. Approaches were flown using a head-down synthetic vision display to evaluate four tunnel (''minimal'', ''box'', ''dynamic pathway'', ''dynamic crow s feet'') and three guidance (''ball'', ''tadpole'', ''follow-me aircraft'') concepts and compare their efficacy to a baseline condition (i.e., no tunnel, ball guidance)...
Keywords: AEROTHERMODYNAMICS; X-33 REUSABLE LAUNCH VEHICLE; COMPUTATIONAL FLUID DYNAMICS; THERMAL PROTECTION; INDUSTRIES; THERMAL ANALYSIS
|ECHO Responds to NASA's Earth Science User Community - Pfister, Robin|
Over the past decade NASA has designed, built, evolved, and operated the Earth Observing System Data and Information System (EOSDIS) Information Management System (IMS) in order to provide user access to NASA's Earth Science data holdings. During this time revolutionary advances in technology have driven changes in NASA's approach to providing an IMS service. This paper will describe NASA's strategic planning and approach to build and evolve the EOSDIS IMS and to serve the evolving needs of NASA...
Keywords: THERMOGRAPHY; VOIDS; JOINTS (JUNCTIONS); INFRARED INSPECTION; NONDESTRUCTIVE TESTS; X-33 REUSABLE LAUNCH VEHICLE; REINFORCEMENT RINGS
|A Geometrical Approach to Bell's Theorem - Rubincam, David Parr|
Bell's theorem can be proved through simple geometrical reasoning, without the need for the Psi function, probability distributions, or calculus. The proof is based on N. David Mermin's explication of the Einstein-Podolsky-Rosen-Bohm experiment, which involves Stern-Gerlach detectors which flash red or green lights when detecting spin-up or spin-down. The statistics of local hidden variable theories for this experiment can be arranged in colored strips from which simple inequalities can be deduc...
Keywords: X-33 REUSABLE LAUNCH VEHICLE; REUSABLE SPACECRAFT; VENTURESTAR LAUNCH VEHICLE; LAUNCHING SITES; LIQUID PROPELLANT ROCKET ENGINES
|Clock Technology Development for the Laser Cooling and Atomic Physics (LCAP) Program - Klipstein, W. M.|
The Time and Frequency Sciences and Technology Group at Jet Propulsion Laboratory (JPL) has developed a laser cooling capability for flight and has been selected by NASA to support the Laser-Cooling and Atomic Physics (LCAP) program. Current work in the group includes design and development for tee two laser-cooled atomic clock experiments which have been selected for flight on the International Space Station.
Keywords: CLOCKS; SKEWNESS; ACCURACY; MODULES; HIGH SPEED; COMPUTERS; X-33 REUSABLE LAUNCH VEHICLE
|Examining INM Accuracy Using Empirical Sound Monitoring and Radar Data - Miller, Nicholas P.|
Aircraft noise measurements were made using noise monitoring systems at Denver International and Minneapolis St. Paul Airports. Measured sound exposure levels for a large number of operations of a wide range of aircraft types were compared with predictions using the FAA's Integrated Noise Model. In general it was observed that measured levels exceeded the predicted levels by a significant margin. These differences varied according to the type of aircraft and also depended on the distance from th...
Keywords: COMPOSITE STRUCTURES; X-38 CREW RETURN VEHICLE; AEROSPACE SAFETY; ULTRASONICS; ACOUSTIC EMISSION; MANUFACTURING; NONDESTRUCTIVE TESTS; REUSABLE LAUNCH VEHICLES; SPACE TRANSPORTATION; COST REDUCTION; DESIGN ANALYSIS; X-33 REUSABLE LAUNCH VEHICLE; X-34 REUSABLE LAUNCH VEHICLE
|Aerospace Medicine and Biology: A Continuing Bibliography With Indexes - NON|
This supplemental issue of Aerospace Medicine and Biology, A Continuing Bibliography with Indexes (NASA/SP#1999-7011) lists reports, articles, and other documents recently announced in the NASA STI Database. In its subject coverage, Aerospace Medicine and Biology concentrates on the biological, physiological, psychological, and environmental effects to which humans are subjected during and following simulated or actual flight in the Earth#s atmosphere or in interplanetary space...
Keywords: SPACECRAFT DESIGN; SPACE SHUTTLE BOOSTERS; NUCLEAR PROPULSION; SPACE SHUTTLES; SPACE TRANSPORTATION SYSTEM; SPACECRAFT PROPULSION; ROCKET ENGINES; X-33 REUSABLE LAUNCH VEHICLE; X-34 REUSABLE LAUNCH VEHICLE; X-38 CREW RETURN VEHICLE; SPACE SHUTTLE MAIN ENGINE
|Summary of Proton Test on the Quick Logic QL3025 at Indiana University - Katz, Richar|
This issue of the Programmable Logic Application Notes is a compilation of topics: (1) Proton irradiation tests were performed on the Quick Logic QL3025 at the Indian University Cyclotron facility. The devices, tests, and results are discussed; (2) The functional failure of EEPROM's in heavy ion environment is presented; (3) the Act 1 architecture is summarized; (4) Antifuse hardness and hardness testing is updated; the single even upset (SEU) response of hardwired flip-flops is also presented; ...
Keywords: CALIBRATING; NEWTON THEORY; POSITION (LOCATION); POTENTIAL FLOW; TRANSONIC SPEED; X-33 REUSABLE LAUNCH VEHICLE; X-34 REUSABLE LAUNCH VEHICLE; X-38 CREW RETURN VEHICLE; DETECTION; FOREBODIES; MATHEMATICAL MODELS; PRESSURE MEASUREMENT; ALGORITHMS; ANGLE OF ATTACK; F-14 AIRCRAFT; MACH NUMBER
|Flexible All-Digital Receiver for Bandwidth Efficient Modulations - Gray, Andrew|
An all-digital high data rate parallel receiver architecture developed jointly by Goddard Space Flight Center and the Jet Propulsion Laboratory is presented. This receiver utilizes only a small number of high speed components along with a majority of lower speed components operating in a parallel frequency domain structure implementable in CMOS, and can currently process up to 600 Mbps with standard QPSK modulation...
Keywords: REUSABLE LAUNCH VEHICLES; EIGENVALUES; OPTIMAL CONTROL; STABILITY; DECOUPLING; ANGULAR VELOCITY; X-33 REUSABLE LAUNCH VEHICLE; LINEAR SYSTEMS; DIFFERENTIAL EQUATIONS; ERRORS
|Product Distribution Theory and Semi-Coordinate Transformations - Airiau, Stephane|
Product Distribution (PD) theory is a new framework for doing distributed adaptive control of a multiagent system (MAS). We introduce the technique of ''coordinate transformations'' in PD theory gradient descent. These transformations selectively couple a few agents with each other into ''meta-agents''. Intuitively, this can be viewed as a generalization of forming binding contracts between those agents...
Keywords: AEROTHERMODYNAMICS; PROTUBERANCES; THERMAL PROTECTION; CONSTRUCTION; ELEVONS; HEAT TRANSFER; X-33 REUSABLE LAUNCH VEHICLE; ACTUATORS; CONTROL SURFACES; DEFLECTION; FLOW DISTRIBUTION
|Atlas of Seasonal Means Simulated by the NSIPP 1 Atmospheric GCM - Bacmeister, Julio|
This atlas documents the climate characteristics of version 1 of the NASA Seasonal-to-Interannual Prediction Project (NSIPP) Atmospheric General Circulation Model (AGCM). The AGCM includes an interactive land model (the Mosaic scheme), and is part of the NSIPP coupled atmosphere-land-ocean model. The results presented here are based on a 20-year (December 1979-November 1999) ''ANIIP-style'' integration of the AGCM in which the monthly-mean sea-surface temperature and sea ice are specified from o...
Keywords: MARS PATHFINDER; NASA SPACE PROGRAMS; X-34 REUSABLE LAUNCH VEHICLE; X-37 VEHICLE; FLIGHT TESTS; SPACECRAFT CONFIGURATIONS; GOVERNMENT/INDUSTRY RELATIONS
|Neural Network and Response Surface Methodology for Rocket Engine Component Optimization - Vaidyanathan, Rajkumar|
The goal of this work is to compare the performance of response surface methodology (RSM) and two types of neural networks (NN) to aid preliminary design of two rocket engine components. A data set of 45 training points and 20 test points obtained from a semi-empirical model based on three design variables is used for a shear coaxial injector element. Data for supersonic turbine design is based on six design variables, 76 training, data and 18 test data obtained from simplified aerodynamic analy...
Keywords: COMBUSTION CHAMBERS; FINITE ELEMENT METHOD; STRUCTURAL ANALYSIS; TEMPERATURE EFFECTS; ROCKET NOZZLES; X-34 REUSABLE LAUNCH VEHICLE; ROCKET ENGINES
|Hypersonic Boundary-Layer Trip Development for Hyper-X - Berry, Scott A.|
Boundary layer trip devices for the Hper-X forebody have been experimentally examined in several wind tunnels. Five different trip configurations were compared in three hypersonic facilities, the LaRC 20-Inch Mach 6 Air Tunnel, the LaRC 31 -Inch Mach 10 Air Tunnel, and in the HYPULSE Reflected Shock Tunnel at GASL. Heat transfer distributions, utilizing the phosphor thermography and thin-film techniques, shock system details, and surface streamline patterns were measured on a 0.333-scale model o...
Keywords: X-34 REUSABLE LAUNCH VEHICLE; FEED SYSTEMS; ROCKET PROPELLANTS; SYSTEMS ENGINEERING; FLOW DISTRIBUTION; FLOW DISTORTION; COMPUTATIONAL FLUID DYNAMICS
|National General Aviation Design Competition Project Report - NON|
This report summarizes the management of the National General Aviation Design Competition on behalf of NASA, the FAA and the Air Force by the Virginia Space Grant Consortium (VSGC) for the time period October 1, 1999 through September 30, 2000. This was the VSGC's sixth year of managing the Competition, which the Consortium originally designed, developed and implemented for NASA and the FAA. The seventh year of the Competition was announced in July 2000...
Keywords: WIND TUNNEL TESTS; AERODYNAMIC DRAG; BASE FLOW; DRAG REDUCTION; X-33 REUSABLE LAUNCH VEHICLE; FOREBODIES; FRICTION DRAG; BOUNDARY LAYERS
|SRS Computer Animation and Drive Train System - Arthun, Daniel|
The spinning rocket simulator (SRS) is an ongoing project at Oral Roberts University. The goal of the SRS is to gather crucial data concerning a spinning rocket under thrust for the purpose of analysis and correction of the coning motion experienced by this type of spacecraft maneuver. The computer animation simulates a virtual, scale model of the component of the SRS that represents the spacecraft itself...
Keywords: COMPUTERIZED SIMULATION; MONTE CARLO METHOD; COMPUTER PROGRAMS; SOFTWARE DEVELOPMENT TOOLS; DISPERSION; X-33 REUSABLE LAUNCH VEHICLE; REFINING
|1-D Numerical Analysis of RBCC Engine Performance - Han, Samuel S|
An RBCC engine combines air breathing and rocket engines into a single engine to increase the specific impulse over an entire flight trajectory. Considerable research pertaining to RBCC propulsion was performed during the 1960's and these engines were revisited recently as a candidate propulsion system for either a single-stage-to-orbit (SSTO) or two-stage-to-orbit (TSTO) launch vehicle. There are a variety of RBCC configurations that had been evaluated and new designs are currently under develo...
Keywords: WIND TUNNEL TESTS; DESIGN ANALYSIS; X-33 REUSABLE LAUNCH VEHICLE; PREDICTION ANALYSIS TECHNIQUES; MATHEMATICAL MODELS; HYPERSONIC SPEED; HIGH TEMPERATURE
|Achieving Space Shuttle ATO Using the Five-Segment Booster (FSB) - Sauvageau, Donald R|
As part of the continuing effort to identify approaches to improve the safety and reliability of the Space Shuttle system, a Five-Segment Booster (FSB) design was conceptualized as a replacement for the current Space Shuttle boosters. The FSB offers a simple, unique approach to improve astronaut safety and increase performance margin. To determine the feasibility of the FSB, a Phase A study effort was sponsored by NASA and directed by the Marshall Space Flight Center...
Keywords: BOLTS; X-33 REUSABLE LAUNCH VEHICLE; DEBONDING (MATERIALS); DEFECTS; JOINTS (JUNCTIONS); SANDWICH STRUCTURES; AUTOCLAVES; FILLETS; HONEYCOMB CORES; LONGERONS
|Adjoint Formulation for an Embedded-Boundary Cartesian Method - Nemec, Marian|
Many problems in aerodynamic design can be characterized by smooth and convex objective functions. This motivates the use of gradient-based algorithms, particularly for problems with a large number of design variables, to efficiently determine optimal shapes and configurations that maximize aerodynamic performance. Accurate and efficient computation of the gradient, however, remains a challenging task...
Keywords: AERODYNAMIC HEATING; HYPERSONIC VEHICLES; COST EFFECTIVENESS; THERMOGRAPHY; X-33 REUSABLE LAUNCH VEHICLE; WIND TUNNEL TESTS; WIND TUNNELS; THERMAL PROTECTION; SINGLE STAGE TO ORBIT VEHICLES; SHOCK WAVE INTERACTION
|Thermographic Analysis of Composite Cobonds on the X-33 - Russell, S. S.|
During the manufacture of the X-33 liquid hydrogen (LH2) Tank 2, a total of 36 reinforcing caps were inspected thermographically. The cured reinforcing sheets of graphite/epoxy were bonded to the tank using a wet cobond process with vacuum bagging and low temperature curing. A foam filler material wedge separated the reinforcing caps from the outer skin of the tank. Manufacturing difficulties caused by a combination of the size of the reinforcing caps and their complex geometry lead to a potenti...
Keywords: FLIGHT CONTROL; TRACKING PROBLEM; SERVOMECHANISMS; PROPORTIONAL CONTROL; MIMO (CONTROL SYSTEMS); QUADRATIC PROGRAMMING; X-33 REUSABLE LAUNCH VEHICLE; FLAPPING; ANGLE OF ATTACK; ITERATION
|Sound Emission of Rotor Induced Deformations of Generator Casings - Polifke, W.|
The casing of large electrical generators can be deformed slightly by the rotor's magnetic field. The sound emission produced by these periodic deformations, which could possibly exceed guaranteed noise emission limits, is analysed analytically and numerically. From the deformation of the casing, the normal velocity of the generator's surface is computed. Taking into account the corresponding symmetry, an analytical solution for the acoustic pressure outside the generator is round in terms of th...
Keywords: POLYMER MATRIX COMPOSITES; LOADS (FORCES); DAMAGE; CHEMICAL REACTIONS; PAYLOADS; LEAKAGE; PROPELLANT TANKS; CRYOGENIC TEMPERATURE; LIQUID HYDROGEN; FAULT DETECTION; COMPOSITE STRUCTURES; X-33 REUSABLE LAUNCH VEHICLE; WEIGHT REDUCTION
|Thermal Performance of LANDSAT-7 ETM Instruments During First Year in Flight - Choi, Michael K|
Landsat-7 was successfully launched into orbit on April 15, 1999. After devoting three months to the t bakeout and cool-down of the radiative cooler, and on- t orbit checkout, the Enhanced Thematic Mapper Plus (ETM) began the normal imaging phase of the mission in mid-July 1999. This paper presents the thermal performance of the ETM from mid-July 1999 to mid-May 2000. The flight temperatures are compared to the yellow temperature limits, and worst cold case and worst hot case flight temperature ...
Keywords: SPACECRAFT GUIDANCE; FLIGHT SAFETY; RISK; CONTROL SYSTEMS DESIGN; SPACECRAFT CONTROL; X-33 REUSABLE LAUNCH VEHICLE; CONTROLLERS; COST REDUCTION; ALGORITHMS; FLIGHT TESTS; DEGREES OF FREEDOM
|A Study of a Lifting Body as a Space Station Crew Exigency Return Vehicle (CERV) - MacConochie, Ian O|
A lifting body is described for use as a return vehicle for crews from a space station. Reentry trajectories, subsystem weights and performance, and costs are included. The baseline vehicle is sized for a crew of eight. An alternate configuration is shown in which only four crew are carried with the extra volume reserved for logistics cargo. A water parachute recovery system is shown as an emergency alternative to a runway landing...
Keywords: NOZZLE DESIGN; ENGINE TESTS; NOZZLE GEOMETRY; ROCKET NOZZLES; PERFORMANCE TESTS; TEST FIRING; GROUND TESTS; X-34 REUSABLE LAUNCH VEHICLE; NOZZLE WALLS; ABLATIVE MATERIALS
|Overview of the NASA AMES-Dryden Integrated Test Facility - Mackall, Dale|
The Integrated Test Facility (ITF), being built at the NASA Ames Research Center's Dryden Flight Research Facility (ADFRF), will provide new real-time test capabilities for emerging research aircraft. An overview of the ITF and the real-time systems being developed to operate this unique facility are outlined in this paper. The ITF will reduce flight test risk by minimizing the difference between the flight- and ground-test environments...
Keywords: SPACECRAFT LAUNCHING; DATA ACQUISITION; ROCKET NOZZLES; X-33 REUSABLE LAUNCH VEHICLE; BASE HEATING; TEST FACILITIES; COST REDUCTION; HYDROGEN; OXYGEN; PROPELLANTS; SOLENOID VALVES
|Overview of the MARS Laser Communications Demonstration Project - Edward, Bernard L.|
This paper provides an overview of the Mars Laser Communications Demonstration Project, a joint project between NASA s Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory, California Institute of Technology (JPL), and the Massachusetts Institute of Technology Lincoln Laboratory (MIT/LL). It reviews the strawman designs for the flight and ground segments, the critical technologies required, and the concept of operations...
Keywords: AIRCRAFT DESIGN; DESIGN ANALYSIS; FLIGHT CHARACTERISTICS; FLIGHT CONTROL; NEURAL NETS; X-33 REUSABLE LAUNCH VEHICLE; MACH NUMBER; PATTERN RECOGNITION; PARAMETER IDENTIFICATION
|SSBUV and NOAA-11 SBUV/2 Solar Variability Measurements - DeLand, Matthew T.|
The Shuttle SBUV (SSBUV) and NOAA-11 SBUV/2 instruments measured solar spectral UV irradiance during the maximum and declining phase of solar cycle 22. The SSB UV data accurately represent the absolute solar UV irradiance between 200-405 nm, and also show the long-term variations during eight flights between October 1989 and January 1996. These data have been used to correct long-term sensitivity changes in the NOAA-11 SBUV/2 data, which provide a near-daily record of solar UV variations over th...
Keywords: X-33 REUSABLE LAUNCH VEHICLE; MAINTENANCE; DECISION MAKING; SMART STRUCTURES; COST REDUCTION; MANAGEMENT SYSTEMS; REUSABLE SPACECRAFT; SINGLE STAGE TO ORBIT VEHICLES; COST EFFECTIVENESS; LOGISTICS
|Pathfinder Program - London, John R., II|
The topics in this viewgraph include: 1) High visibility Flight Projects; 2) Pathfinder Flight Experiments; 3) X-37 Configuration Modification Options; 4) Flight Testing for a Multistage Reusable System; 5) X-34 Vehicle Description; 6) X-34 Expanded View; 7) Vehicle Size Comparison; 8) X-34 Experiment Status; 9) Government Participation; 10) Government and Industry Participants; 11) X-34 Project Status; 12) X-34 Captive Carry Fight; 13) Little Joe III; 14) Fastpac; and 15) Islunar Tug.
Keywords: X-34 REUSABLE LAUNCH VEHICLE; PIGGYBACK SYSTEMS; PROPULSION SYSTEM CONFIGURATIONS; REUSABLE SPACECRAFT; AEROSPACE ENGINEERING; AEROSPACE PLANES; LAUNCH VEHICLES; PROTOTYPES; LAUNCH COSTS; AIR LAUNCHING; THERMAL PROTECTION
|Simulated Atomic Fission Engine (S.A.F.E) - VanDyke, Meliss|
This paper presents viewgraphs of S.A.F.E. (Simulated Atomic Fission Engine). The topics include: 1) Why Space Fission Propulsion 2) History of Fission System Development; 3) New Approach to Space Fission Propulsion System Development; 4) Propulsion Flight Demonstrator Schematic Flight Configuration; 5) Ongoing Propellant Energy Source Tests; 6) First Generation Propulsion System Status; 7) Tungsten Fuel Pin Simulator Tests; 8) Full Module Test (High Efficiency Mode); and 9) First Generation Pro...
Keywords: X-34 REUSABLE LAUNCH VEHICLE; LOADS (FORCES); ROCKET ENGINE DESIGN; DYNAMIC STRUCTURAL ANALYSIS; FINITE ELEMENT METHOD; COST REDUCTION; NOZZLE DESIGN; STEADY STATE
|Cloud Statistics for NASA Climate Change Studies - Wylie, Donald P|
The Principal Investigator participated in two field experiments and developed a global data set on cirrus cloud frequency and optical depth to aid the development of numerical models of climate. Four papers were published under this grant. The accomplishments are summarized: (1) In SUCCESS (SUbsonic aircraft: Contrail & Cloud Effects Special Study) the Principal Investigator aided weather forecasters in the start of the field program...
Keywords: WIND TUNNEL TESTS; GROUND EFFECT (AERODYNAMICS); AERODYNAMIC CHARACTERISTICS; DATA BASES; FLIGHT SIMULATION; DATA SIMULATION; X-34 REUSABLE LAUNCH VEHICLE; SUBSONIC SPEED; HYPERSONIC SPEED; MACH NUMBER
|Inviscid Design of Hypersonic Wind Tunnel Nozzles for a Real Gas - Korte, J. J|
A straightforward procedure has been developed to quickly determine an inviscid design of a hypersonic wind tunnel nozzle when the test crash is both calorically and thermally imperfect. This real gas procedure divides the nozzle into four distinct parts: subsonic, throat to conical, conical, and turning flow regions. The design process is greatly simplified by treating the imperfect gas effects only in the source flow region...
Keywords: LEAKAGE; SR-71 AIRCRAFT; LIQUID OXYGEN; HYDROGEN; CONCENTRATION (COMPOSITION); X-33 REUSABLE LAUNCH VEHICLE; AEROSPIKE ENGINES; GAS DETECTORS; PRESSURE SENSORS; FEED SYSTEMS; FLIGHT TESTS; FLAMMABILITY; FLIGHT SAFETY; HAZARDS
|Effect of Shear Deformation and Continuity on Delamination Modelling with Plate Elements - Glaessgen, E. H.|
The effects of several critical assumptions and parameters on the computation of strain energy release rates for delamination and debond configurations modeled with plate elements have been quantified. The method of calculation is based on the virtual crack closure technique (VCCT), and models that model the upper and lower surface of the delamination or debond with two-dimensional (2D) plate elements rather than three-dimensional (3D) solid elements...
Keywords: AERODYNAMIC CHARACTERISTICS; AERODYNAMIC HEATING; COMPUTATIONAL FLUID DYNAMICS; FLIGHT CONDITIONS; EULER EQUATIONS OF MOTION; NAVIER-STOKES EQUATION; TURBULENCE; X-33 REUSABLE LAUNCH VEHICLE; WIND TUNNELS
|Neural Networks for Rapid Design and Analysis - Sparks, Dean W., Jr.|
Artificial neural networks have been employed for rapid and efficient dynamics and control analysis of flexible systems. Specifically, feedforward neural networks are designed to approximate nonlinear dynamic components over prescribed input ranges, and are used in simulations as a means to speed up the overall time response analysis process. To capture the recursive nature of dynamic components with artificial neural networks, recurrent networks, which use state feedback with the appropriate nu...
Keywords: AERODYNAMIC CHARACTERISTICS; X-33 REUSABLE LAUNCH VEHICLE; SCALE MODELS; JET CONTROL; HYPERSONIC FLIGHT; ANGLE OF ATTACK; SINGLE STAGE TO ORBIT VEHICLES; MACH NUMBER; HYPERSONIC SPEED
|Vibrating Systems with Singular Mass-Inertia Matrices - Balakrishnan, A. V|
Vibrating systems with singular mass-inertia matrices arise in recent continuum models of Smart Structures (beams with PZT strips) in assessing the damping attainable with rate feedback. While they do not quite yield 'distributed' controls, we show that they can provide a fixed nonzero lower bound for the damping coefficient at all mode frequencies. The mathematical machinery for modelling the motion involves the theory of Semigroups of Operators...
Keywords: X-34 REUSABLE LAUNCH VEHICLE; SIMULATION; VENTS; LIQUID ROCKET PROPELLANTS; LIQUID PROPELLANT ROCKET ENGINES; LIQUID OXYGEN; HYPERSONIC VEHICLES; EVAPORATION; PROPELLANT TANKS; PROPELLANTS; PROPULSION
|A Plasmoid Thruster for Space Propulsion - Koelfgen, Syri J.|
There are a number of possible advantages to using accelerated plasmoids for in-space propulsion. A plasmoid is a compact plasma structure with an integral magnetic field. They have been studied extensively in controlled fusion research and are classified according to the relative strength of the poloidal and toroidal magnetic field (B(sub p), and B(sub t), respectively). An object with B(sub p), / B(sub t) much greater than 1 is classified as a Field Reversed Configuration (FRC); if B(sub p) ap...
Keywords: X-33 REUSABLE LAUNCH VEHICLE; BRAGG GRATINGS; SYSTEMS HEALTH MONITORING; MANAGEMENT SYSTEMS; SYSTEMS INTEGRATION; FLIGHT TESTS; F-18 AIRCRAFT; COMMUNICATION EQUIPMENT; DATA TRANSMISSION; FIBER OPTICS
|A Note on Trapping Moving Vortices - Kao, Hsiao C|
The topic of stationary configurations of point vortices, also known as vortex equilibrium, has received considerable attention in recent years. By observing numerical results, it is found that a ''counterpart'' of this system also exists, in which moving vortices may be ''trapped'' by an inlet-like device to form a stationary pattern with no translational motion. After an intuitive explanation for the process, vortex trajectory maps based on numerical results are presented...
Keywords: FLIGHT CONTROL; DIFFERENTIAL EQUATIONS; COST REDUCTION; X-33 REUSABLE LAUNCH VEHICLE; ENGINE FAILURE; ANGULAR VELOCITY; AEROSPIKE ENGINES; FLIGHT SIMULATION; ROBUSTNESS (MATHEMATICS); TRAJECTORIES; EIGENVALUES
|Analysis of Fuel Vaporization, Fuel-Air Mixing, and Combustion in Integrated Mixer-Flame Holders - Deur, J. M.|
Requirements to limit pollutant emissions from the gas turbine engines for the future High-Speed Civil Transport (HSCT) have led to consideration of various low-emission combustor concepts. One such concept is the Integrated Mixer-Flame Holder (IMFH). This report describes a series of IMFH analyses performed with KIVA-II, a multi-dimensional CFD code for problems involving sprays, turbulence, and combustion...
Keywords: AERODYNAMIC HEATING; BOUNDARY LAYER TRANSITION; HYPERSONIC BOUNDARY LAYER; X-33 REUSABLE LAUNCH VEHICLE; SURFACE ROUGHNESS; HYPERSONIC SPEED; REYNOLDS NUMBER; SCALE MODELS
|Spacecraft Compartment Venting - Scialdone, John J|
At various time concerns have been expressed that rapid decompressions of compartments of gas pockets and thermal blankets during spacecraft launches may have caused pressure differentials across their walls sufficient to cause minor structural failures, separations of adhesively-joined parts, ballooning, and flapping of blankets. This paper presents a close form equation expressing the expected pressure differentials across the walls of a compartment as a function of the external to the volume ...
Keywords: X-33 REUSABLE LAUNCH VEHICLE; TRANSITION FLIGHT; CONTROL ROCKETS; GUIDANCE SENSORS; AIRBORNE/SPACEBORNE COMPUTERS; APPLICATIONS PROGRAMS (COMPUTERS); FLIGHT CONTROL; CONTROL SIMULATION; ENGINE FAILURE; LAUNCHING; PROTOTYPES; TRAJECTORIES
|Optimizing Sensor and Actuator Arrays for ASAC Noise Control - Palumbo, Dan|
This paper summarizes the development of an approach to optimizing the locations for arrays of sensors and actuators in active noise control systems. A type of directed combinatorial search, called Tabu Search, is used to select an optimal configuration from a much larger set of candidate locations. The benefit of using an optimized set is demonstrated. The importance of limiting actuator forces to realistic levels when evaluating the cost function is discussed...
Keywords: X-33 REUSABLE LAUNCH VEHICLE; INSPECTION; THERMOGRAPHY; INFRARED IMAGERY; LIQUID HYDROGEN; PROPELLANT TANKS; STORAGE TANKS; FUEL TANKS; MANUFACTURING; GRAPHITE-EPOXY COMPOSITES; REINFORCING MATERIALS; SEALS (STOPPERS)
|NASA Connect - FoF - Computer Simulation - NASA LaRC Office of Education|
NASA Connect Segment explaining how NASA uses computer simulation to design spacecraft, including the next reusable launch vehicle.
Keywords: NASA Connect; Collaborative Engineering Center; CEC; NASA Marshall; Estimating; Thermal Protection Systems; TPS; Software; Hardware; Computer Simulation; Spacecraft; RLV; Reusable Launch Vehicle
|NASA Connect - FoF - RLVs - NASA LaRC Office of Education|
NASA Connect Segment explaining how Reusable Launch Vehicles are designed and used by NASA for launch, space travel, and re-entry.
Keywords: NASA Connect; Jennifer Pulley; Kathy Kynard; Marshall Space Flight Center; RLV; Reusable Launch Vehicle; Design; Booster; Thermal Protection System; TPS; Re-entry
|Stress Formulation in Three-Dimensional Elasticity - Patnaik, Surya N.|
The theory of elasticity evolved over centuries through the contributions of eminent scientists like Cauchy, Navier, Hooke Saint Venant, and others. It was deemed complete when Saint Venant provided the strain formulation in 1860. However, unlike Cauchy, who addressed equilibrium in the field and on the boundary, the strain formulation was confined only to the field. Saint Venant overlooked the compatibility on the boundary...
Keywords: X-33 REUSABLE LAUNCH VEHICLE; ACTUATORS; STABILITY; CONFIGURATION MANAGEMENT; CONTROL SYSTEMS DESIGN; FLIGHT ENVELOPES; FLIGHT CONTROL; CONTROL THEORY; MIXERS; DEGREES OF FREEDOM; CONTROL SURFACES
|SeaWiFS Postlaunch Technical Report Series Cumulative Index: Volumes 1-23 - NON|
The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) is the follow-on ocean color instrument to the Coastal Zone Color Scanner (CZCS), which ceased operations in 1986, after an eight-year mission. SeaWiFS was launched on 1 August 1997, onboard the OrbView-2 satellite, built by Orbital Sciences Corporation (OSC). The SeaWiFS Project at the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC), undertook the responsibility of documenting all aspects of this mission...
Keywords: ENGINE TESTS; FULL SCALE TESTS; PROPELLANT TESTS; TEST FACILITIES; X-33 REUSABLE LAUNCH VEHICLE; AEROSPIKE ENGINES; LOW COST; THRUST CHAMBERS; SOUNDING ROCKETS
|Application of Forebody Strakes for Directional Stability and Control of Transport Aircraft - Shah, Gautam H.|
A brief overview of a cooperative NASA/Boeing research effort, Strake Technology Research Application to Transport Aircraft (STRATA), intended to explore the potential of applying forebody strake technology to transport aircraft configurations for directional stability and control at low angles of attack, is presented. As an initial step in the STRATA program, an exploratory wind-tunnel investigation of the effect of fixed forebody strakes on the directional stability and control characteristics...
Keywords: AEROTHERMODYNAMICS; X-38 CREW RETURN VEHICLE; HYPERSONIC SPEED; RELIABILITY; REYNOLDS NUMBER; AERODYNAMIC CHARACTERISTICS; METHANE; PRESSURE DEPENDENCE; PHOSPHORS; DATA ACQUISITION; FLOW DISTRIBUTION; REUSABLE LAUNCH VEHICLES; TECHNOLOGY UTILIZATION; NASA PROGRAMS; WIND TUNNEL TESTS; HYPERSONIC WIND TUNNELS; COMPUTATIONAL FLUID DYNAMICS; X-33 REUSABLE LAUNCH VEHICLE; X-34 REUSABLE LAUNCH VEHICLE
|Astrobiology Exploration Strategies for the Mars Polar Regions Using Balloon Platforms - Mahaffy, P. R.|
Montgolfiere balloons can provide a unique near-surface platform for an extended traverse over the polar regions of Mars. During the polar summer, such solar powered balloons would remain in the constant sun of the polar summer and could remain airborne for many weeks or even months as the atmospheric circulation would drive the balloons around the polar region many times before the balloon would cross the terminator...
Keywords: COMPUTATIONAL FLUID DYNAMICS; X-33 REUSABLE LAUNCH VEHICLE; AIRCRAFT WAKES; GRID GENERATION (MATHEMATICS); TOPOLOGY; COMPUTER PROGRAMS; VENTURESTAR LAUNCH VEHICLE; COMPUTER AIDED DESIGN; GRAPHICAL USER INTERFACE; COMPUTERIZED SIMULATION; DATA SMOOTHING
|Modal Behavior of Hemispheric Sea Ice Covers - Gloersen, Per|
Recent papers have described 18-year trends and annual oscillations in the Arctic and Antarctic sea ice extents, areas, and enclosed open water areas based on a newly-formulated 18.2-year ice concentration time series. This time series includes data for the entire Arctic and Antarctic ice covers, as well as for previously defined subregions consisting of 5 sectors in the Antarctic and 9 regions in the Arctic...
Keywords: X-33 REUSABLE LAUNCH VEHICLE; REUSABLE SPACECRAFT; AERODYNAMICS; TERMINAL AREA ENERGY MANAGEMENT; LIQUID SLOSHING; LAUNCHING; FLEXIBILITY; CONTROL EQUIPMENT; ASCENT; AEROSPIKE ENGINES; PROPELLANT TANKS; MACH NUMBER; FLIGHT CONTROL; ENGINE CONTROL; CONTROL SYSTEMS DESIGN; ATTITUDE CONTROL; RECOVERABLE LAUNCH VEHICLES
|Lateral Shock of the R Aquarii Jet - Hollis, J. M.|
The R Aqr jet was observed with the VLA B-configuration at two epochs separated by approximately 13.2 yr. Comparison of the resulting 6 cm continuum images show that the radio jet has undergone a lateral counterclockwise rotation of approximately 6 deg-12 deg on the plane of the sky. The model of jet parcels on independent trajectories is difficult to reconcile with these observations and leads us to consider a path-oriented jet (i.e., younger parcels follow the same path as older parcels)...
Keywords: AEROSPIKE ENGINES; X-33 REUSABLE LAUNCH VEHICLE; COMPUTATIONAL FLUID DYNAMICS; FINITE DIFFERENCE THEORY; FLOW DISTRIBUTION; FOREBODIES; HEAT FLUX; POTENTIAL FLOW; VISCOUS FLOW; PLUMES; BASE HEATING; BOUNDARY LAYER SEPARATION; CONVECTIVE HEAT TRANSFER; GRAY GAS; HEAT TRANSFER; SEPARATED FLOW; THREE DIMENSIONAL FLOW
|Self-Similar Compressible Free Vortices - vonEllenrieder, Kar|
Lie group methods are used to find both exact and numerical similarity solutions for compressible perturbations to all incompressible, two-dimensional, axisymmetric vortex reference flow. The reference flow vorticity satisfies an eigenvalue problem for which the solutions are a set of two-dimensional, self-similar, incompressible vortices. These solutions are augmented by deriving a conserved quantity for each eigenvalue, and identifying a Lie group which leaves the reference flow equations inva...
Keywords: X-33 REUSABLE LAUNCH VEHICLE; ELECTROMECHANICAL DEVICES; HARNESSES; HEALTH; NOZZLE DESIGN; NOZZLE GEOMETRY; TRAJECTORIES; VALVES; YAW; CONTROL SYSTEMS DESIGN; AEROSPIKE ENGINES; ENGINE CONTROL; SINGLE STAGE TO ORBIT VEHICLES; THROTTLING; THRUST CONTROL; THRUST VECTOR CONTROL; ACTUATORS
|NASA Destination Tomorrow - Episode 11 - NASA LaRC Office of Education|
NASA Destination Tomorrow Video containing five segments as described below. NASA Destination Tomorrow Segment describing how NASA atmospheric scientists contributed to the conservation of the Declaration of Independence, the Constitution, and the Bill of
Keywords: Tech Watch; Tonya St. Romain; Declaration Of Independence; Constitution; Bill Of Rights; Dr. Joel Levine; How It Works; Johnny Alonso; GPS; Global Positioning System; Dr. Kevin Dutton; On The Runway; Reusable Launch Vehicle; RLV; Space Shuttle; Stephanie